c) Frankel and Korie would not be making a celebrated Broadway debut with one of the most accomplished scores of the past decade.

The women are Edith Bouvier Beale and her daughter "Little Edie," respectively aunt and cousin of Jacqueline Kennedy Onassis. They declined from high society in the 1940s to tabloid notoriety in the 1970s when it became known they were living in squalor in their dilapidated Long Island, N.Y., mansion with 52 cats. Frankel, Korie and book writer Doug Wright based their show on Grey Gardens, the 1975 cult documentary about the Beales.

Most would have deemed it an unlikely source for a musical.

"We look for edgy projects," Korie says. "We believe we should write what we love, then hope and pray that intersects with public taste — rather than try to produce what the public will want. We go to the theater to be surprised."

Show goers are surprised at how moved they are by the hilarious yet heartbreaking plight of Grey Gardens' willfully eccentric mother-daughter duo.

"I love watching the audience watching it," Korie says. "There's a moment of uncertainty at the start. Then they get pulled in, as you would with a play."

"You may feel you can keep them at arm's length, due to their peculiarities," Frankel says. "But though their situation is extreme, you find it touches feelings about your own family ties. Everyone has, or will have, a frail, incapacitated parent and have to decide how to deal with them. And from the other side, we all face the challenge of becoming a fully functioning adult and successfully separating from the parent — which Edie can't quite achieve."

Though also a fan of the film, Korie at first doubted its musical prospects. "Then I watched it again. When I saw the scene of mama Edith in bed, cooking corn on the hot plate for Jerry (the slacker teen who does odd jobs for the recluses), I realized this scene has everything: mother-daughter love and rivalry, Edie trying to take care of Edith in her fashion, Edith aggravating Edie by holding up Jerry as an an example. It could be a song."

Indeed, it became one of the show's best numbers, Jerry Likes My Corn.

To write the show's book, they approached Wright, the Pulitzer- and Tony-winning I Am My Own Wife playwright, who'd been Frankel's classmate at Yale University. "We thought he might be a fan of the film," Korie says. "He was so big a fan that he didn't want to write it as a musical."

"He kept turning us down," says Frankel, "saying, 'The film's brilliant but not a narrative. I don't know how to do a book musical where nothing happens.' "

They toyed with various solutions yet remained at an impasse for months as their option to adapt the film was about to run out.

"Then one day, while Scott and I were at a restaurant," Korie says, "he started doodling on the tablecloth. He drew two boxes with a white space in between and said, 'That's it.' We would divide the show into two eras."

"By setting the first act in 1941," Frankel says, "we could ask, 'What happened? What went wrong?' and let the audience see what their lives were like before everything went south. We could take the style of the theater of that day, like a Philip Barry play, reference those songs and styles."

"That sold Doug on it, too," Korie says. "He could create a mythic past for them based on the things they said in the movie — but with everything happening on one fateful day."

In the imagined 1941 prequel, Edith prepares for the the party announcing Edie's engagement to Joe Kennedy Jr. By end of the act, Edie's engagement is broken, and Edith learns her husband (whom the family has been awaiting through the act) has run off with another woman. Cue the ladies' Act 2 decline.

Along with the two-era format came another innovation. One actress would play manipulative socialite Edith at her midlife prime in Act 1, then derailed debutante Edie as a 50ish wreck in Act 2.

"We had Christine in mind from the start," Korie says of the esteemed veteran, a Tony winner as the tempestuous, injury-prone diva in the 2001 revival of 42nd Street. When they first attempted to approach her about the show, an intermediary warned they'd have little chance of getting her.

"We said, 'Just try it,' " Korie recalls. "Unbeknownst to us, she was a Grey Gardens aficionada and agreed immediately." They wrote key numbers for her, including Another Winter in a Summer Town, Edie's stunning final solo in which she realizes she will never escape her mother.

"She's a genius," Korie says of their star. "And, you know, it's hugely demanding. She sings twice as many songs as Rose in Gypsy."

"Another key factor is that Edith and Edie were both frustrated performers," Frankel says. "In the documentary, they're always singing old songs like Tea for Two. We didn't want to use old songs, which gave us the chance to write pastiche numbers for those spots."

Grey Gardens boasts the most artful use of pastiche since Follies, another work juxtaposing a lost golden past and its ruined remains. Such numbers as the operettaish Will You?, Drift Away and the duet Peas in a Pod are at once perfect evocations of period song styles and beautifully crafted tunes in their own right.

Even after the show's well-received off-Broadway run last spring, the team made considerable refinements before its November opening on Broadway.

"I'm amazed at all that's happened with the show," Frankel says. "I mean, Broadway is increasingly about big flashy brand-name musicals based on big popular films. But we're a boutique musical based on a quirky documentary. That we're even here says something encouraging about audiences, about the possibilities for musicals in this day and age."